You can own a gun in a free society but that means you can literally shoot yourself in the foot with it.

If I bought a bunch of Euros and found the next day I couldn't spend them. I would feel there was something fundamentally wrong with the system of this money. Now how should this be different if it is Steem and @justinsuntron instead?

By undermining the social contract of your keys your coins, it casts doubt on the currency in general.

But it also has its strengths. Did you know that it is possible on the blockchain level of Steem to have accounts with multiple owner key pairs, active key pairs, and posting key pairs? I have done these things. I have done multi-signature transactions on one of the test nets.